Noise transmission from a curved panel into a cylindrical enclosure: Analysis of structural acoustic coupling

Much of the research on sound transmission through the aircraft fuselage in to the interior of aircraft has considered coupling of the entire cylinder to the acoustic modes of the enclosure; Yet, much of the work on structural acoustic control of sound radiation has focused on reducing sound radiatio n from individual panels into an acoustic space. Research by the authors se eks to bridge this gap by considering the transmission of sound from indivi dual panels on the fuselage to the interior of the aircraft. As part of thi s research, an analytical model of a curved panel, with attached piezoelect ric actuators, subjected to a static pressure load was previously developed . In the present work, the analytical model is extended to consider the cou pling of a curved panel to the interior acoustics of a rigid-walled cylinde r. Insight gained from an accurate analytical model of the dynamics of the noise transmission from the curved panels of the fuselage into the cylindri cal enclosure of an aircraft is essential to the development of feedback co ntrol systems for the control of stochastic inputs, such as turbulent bound ary layer excitation. The criteria for maximal structural acoustic coupling between the modes of the curved panel and the modes of the cylindrical enc losure are studied. For panels with aspect ratios typical of those found in aircraft, results indicate that predominately axial structural modes coupl e most efficiently to the acoustic modes of the enclosure. The effects of t he position of the curved panel on the cylinder are also studied. Structura l acoustic coupling is found to not be significantly affected by varying pa nel position. The impact of the findings of this study on structural acoust ic control design is discussed. (C) 2001 Acoustical Society of America.